Beginners Guide to Macro Photography
It’s a natural urge for any person wielding a camera to attempt to take close-up shots of objects around theme. Close-ups of small objects, when viewed at the full multi-megapixel resolution of modern cameras, appear surrealistic and reveal details that we had not previously imagined to be present.
Close Up Photography vs. Macro Photography vs. Photo Micrography
It is important to know the difference between close-up photography and Macro photography.
- If you zoom in to the subject using the magnification power of your lens, thus making the object appear really close, it is defined as close-up photography. Photographs of the moon, close-up photographs of birds on trees and bees on flowers are examples of close-up photography.
- Macro photography (Nikon calls it Micro Photography) is defined as a close-up photography where the ratio of actual size of object to size of object on the image sensor, is better than 1:2. This ratio is called the Maximum Magnification Ratio (MRR). Most dedicated macro lenses feature a MRR of 1:1
- Photo Micrography is defined as photos taken through a microscope. Clearly, such images have MRR of 10:1 or better. Most laboratory microscopes come with 100:1 magnification lenses.
For most common purposes, photos taken with 1:6 – 1:3 MRR are considered as close-up photography, 1:2 – 3:1 are considered as macro photography and 5:1 – 100:1 is considered as photo micrography.
Case Study: Tamron 18-200 mm Macro lens with MRR of 1:2
- If I am shooting a square diamond that is 5 x 5 mm, it’s maximum size on the sensor will be 2.5 x 2.5mm (1:2 reduction)
- My Nikon D5100 features a Nikon DX sensor (APS-C size, 23.6 x 15.6 mm), the diamond width will be 10.5932 % of the sensor width (2.5 mm of 23.6 mm) and height will be 16.0256 % of the sensor height (2.5 mm of 15.6 mm)
- The Nikon D5100 sensor produces 16 Megapixel images (4,928 x 3,264 pixels), the effective number of pixels for used for the diamond image will be 522 x 522 pixels (10.5932 % of 4,928 pixels).
- Thus, just the diamond image area has 2,72,484 pixels (522 x 522) and it is a 0.27 MP image (2,72,484 / 1 million). If the image is printed at 300 dpi, it’s dimensions on the printed page will be 1.74 x 1.74 inches (522 pixels / 300 dots per inch).
Case Study: Tamron 90 mm Macro lens with MRR of 1:1
- If I am shooting a square diamond that is 5 x 5 mm, it’s maximum size on the sensor will be 5 x 5 mm (1:1 reduction)
- My Nikon D5100 features a Nikon DX sensor (APS-C size, 23.6 x 15.6 mm), the diamond width will be 21.1864 % of the sensor width (5 mm of 23.6 mm) and height will be 32.0512 % of the sensor height (5 mm of 15.6 mm)
- The Nikon D5100 sensor produces 16 Megapixel images (4,928 x 3,264 pixels), the effective number of pixels for used for the diamond image will be 1044 x 1044 pixels 21.1864 % of 4,928 pixels).
- Thus, just the diamond image area has 10,89,936 pixels (1,044 x 1,044) and it is a 1 MP image (10,89,936 / 1 million). If the image is printed at 300 dpi, it’s dimensions on the printed page will be 3.48 x 3.48 inches (1,044 pixels / 300 dots per inch).
Clearly, photographing with a 1:1 capable macro lens (versus a 1:2 capable macro lens) has quadrupled the number of pixels in applicable image area; thus leading to greater definition of the subject in the resulting image.
Coming back to “Macro Photography”, photography using a dedicated 1:1 capable Macro lenses is always an optimum solution, but for those who are constrained by their budgets, other options are available:
These are rings that increase the distance between the last element of the lens and the sensor, thus increasing the focal length and resulting in greater ‘magnification power’. Normally, the lens attaches directly to the lens bayonet on the camera body. Extender tubes accept the lens on one end and attach to the camera body on the other. The increased gap caused by the extender tube causes magnification by a factory typically 1.4x or higher.
Extender tubes allow non-macro lenses such as the kit 18-55 lens (MRR 1:3) to take images with magnification better than 1:2 lenses!
You can craft extender tubes at home using thick ‘Pringles’ or ‘Tennis ball’ containers, but such tubes completely kill the communication between the lens and the camera and such tubes can only be used with lens & camera combinations where complete manual control is possible. For example, the new Nikon ‘G’ series lenses do not have manual ‘Aperture Control’ ring and thus are hard to use with manual tubes. Most new Nikon cameras also have trouble calculating exposure and setting shutter speeds when the lens is no longer communicating with the camera.
Most commercially available extender tubes transmit ‘some’ information from the lens to the camera and this allows for automatic setting of aperture and shutter speed. Very few extender tubes send ‘Focus confirmation’ information and such tubes are so expensive that you are better off buying a dedicated macro lens.
Extender tubes also come in form of ‘Bellows’. This allows the utmost flexibility in composition of the image. Expensive bellow rigs also feature focusing rails so that the camera can be moved in millimeter increments for fine focusing.
Macro Conversion Lens / Close-up Filters / Tele Convertor Lens
A much better solution is a macro conversion lens like the Raynox DCR 250. Such lenses snap-on in front of your existing non-macro lens and present a pre-magnified image to the front element of your lens. The single biggest advantage of these lenses is the fact that they keep the communication link between your lens and the camera body intact and your camera can focus normally and set the aperture and shutter speed automatically. Since many of these lenses also use a spring mechanism to snap-on, you can fit them on lenses ranging from 52 – 58mm filter diameter.
Most Close-Up Filter lenses come in the form of filter rings that you need to screw in front of your existing lens. Here is it important to purchase the lens of a matching diameter. Close-up adapter are generally very economical to offer image quality comparable to Macro-conversion lenses but not the magnification of macro-conversion lenses.
Tele Converter Lens sit between the main lens and the lens body and magnify the image produced by the main lens by a small factor (2x is common) and present to the sensor. Tele converter rings are not commonly used for macro photography and they are commonly used to magnify the focal length of telephoto lenses such as 500 mm mirror lens.
A problem with these Macro Conversion lenses is the extremely shallow Depth of Field (DOF). DOF is area of the image that is in sharp focus (technically it is defined as the thickness of the image plane). Macro Conversion lenses reduce DOF drastically and allow only a very small part of the image to be in sharp focus. While the magnification effect is terrific, parts of the image that are in-front/behind-of the focus point, are completed out of focus (blurred).
The small DOF of Macro Conversion lens can be used for terrific creative effects but requires terrific patience and almost always fine Manual Focusing to achieve good results.
Lens Reverse Mount Adapter
A typical lens is designed to take in a large angle of view and shrink it so that it can fit into the dimensions of a smaller sensor area. Hence, the front element of the lens is larger than the back (last) element of the lens. By reversing the lens, we can achieve the opposite – take smaller area and magnify it so that the sensor capture only a small part of the magnified image, thus magnifying the subject even more.
Lens Reversal rings are available quite cheaply that allow mounting of common lenses such as the kit 18-55 mm lens on the the camera and achieve macro magnification better than even 1:1 macro lenses.
Like manual extension tubes, such rings completely cut-off communication between the lens and the camera and thus make the photography session completely manual. In fact, best results are often obtained by using old (20-30) year old fully-manual lenses rather than new lenses where even Aperture cannot be set manually (for example Nikon G series lenses). Newer lenses can be used, but generally require using sticky-tape to keep the aperture-lever in ‘open’ position
Rings are also available that allow two lenses to be mounted together to achieve much finer control over magnification of the image and thus improve composition.
Some cameras refuse to shoot if they do not receive any lens communication and such cameras have to configure to shoot without lens (for example, Sony DSLRs).
Challenges of Macro Photography
Macro Photography is not only aesthetically challenging, it is very technically challenging too. Common problems are:
Shallow Depth of Field
Most macro photography setups (even those using dedicated macro lenses) have to cope with a very shallow DOF. This results in a very small area of the subject being in sharp focus. For example, you may discover that while you want a close-up of a bee, the lens is unable to sharply focus on the entire bee; only a smaller part of the bee is in sharp focus.
The situation can be saved in two ways:
- Small Aperture: A smaller aperture can result in the image being sharper across a wider depth. For example, setting F/8 on the F/2.8 capable Tamron 90 mm lens. This needs to be done with care since every lens has a sweet DOF, beyond which the focus again gets soft because of excessive diffraction of light. For example, setting F/22 on the Tamrom 90 mm lens always results in soft images. Needless to say, as the lens aperture is reduced, available light is reduced, shutter speed goes up and tripod based shooting becomes mandatory.
- Stacking: A digital technique called stacking allows the photographer to take multiple images of the subject with different parts of the subject being in sharp focus. The images are later combined in software to arrive at the final image where the subject is entirely in sharp focus. For example, we may shoot 3 images of the bee so that it’s head – body – tail are in sharp focus and then combine them into an image in which the entire bee is in sharp focus.
In macro photography, at times, the shallow DOF is only 1 mm across. This results in achieving sharp focus extremely challenging. Often, Auto-focus mechanisms of camera, particularly those that are contrast based, either fail or focus incorrectly. Manual focusing is quite difficult too since the focusing ring of the lens may not allow for very fine focusing (very less travel) or may be turned even with the action of the fingers leaving the focusing ring after achieving fine focus.
The solution to this lies in moving the entire camera, kinda like the adage if the well cannot come to the horse, the horse will have to travel to the well.
Macro Focusing Rails are available that can be mounted on tripods securely. The camera is mounted on the rails. When approximate focus has been achieved using the focusing ring on the lens, knobs on the rails are rotated to move the camera back and forth in millimeter increments and achieve accurate focus.
Many macro focusing rails also have horizontal adjustments so that the camera can be moved laterally to cope with the movement of the subject.
Another challenge of macro photography is the working distance. If shooting tiny insects, it helps to shoot from a distance. Not only, you avoid the risk of being bitten, you also do not disturb the natural environment of the creatures. Shooting from a distance also avoids the shadows that may be rendered on the scene by the camera equipment and the photographer.
Dedicated macro lens allow for suitable working distance. Lenses with 40 mm – 200 mm focal lengths are available which greatly increase the working distance. Needless to say, the higher the working distance, the more complicated and expensive the lens gets.
Lighting poses quite a lot of challenge in macro photography. Since only a tiny area of the environment is sampled, the amount of light entering the lens is quite lens and macro photographs without additional lighting can appear dull and lifeless.
Fortunately, lighting is fixed with simple mirrors / screens reflecting additional light onto the scene. More expensive options include Macro Lens Flash Rings that provide continuous light. These flash rings are mounted around the lens and focus light directly on the subject in focus.
Like the subject, tiny errors in photography are magnified many times in Macro photography. Chief among them is blurring caused due to vibration. If your camera vibrates 2 mm during shooting a football match scene, the effect is barely noticeable in the final image and most ‘Image Stabilisers’ easily compensate for it. On the other hand, when shooting macro photography at 1:1, a 2 mm vibration results in a direct shift of 2 mm distance in the subject in focus. That’s almost 10% of the image!
As a result, photographers of macro have to be particularly careful to avoid vibration. A few quick solutions are:
- Sturdy Tripod: Most lightweight tripods have very thin legs touching the ground and these are susceptible to pick up tiny vibrations caused even by a gentle wind or stomping. Heavy tripods tend to dampen such vibrations and provide a stable platform.
- Sand Bags: At times, even the most sturdy tripod requires further stabilization. This can be achieved by lowering it’s center of gravity. If the tripod features a hook in the center column, a bag of sand can be hung to weigh down the tripod center and lower it’s center of gravity closer to the ground.
- Bean Bags: If the ground beneath the tripod is hard, vibrations travel quite easily up the tripod columns. To avoid these, the tripod can be armed with rubber feet or the legs can be placed on small bean bags which will absorb the ground vibration.
- Mirror Lockup: Most DSLR cameras use a Prism / Mirror to divert the light coming into through the lens to the optical view-finder. When the shutter button is pressed, the prism/mirror is moved out of the way to allow it to fall directly on the sensor to capture the image. This mechanism can set off vibrations in the mechanics of the camera and cause ‘camera shake’. Cameras that feature ‘Mirror lockup’ or ‘Quiet mode’ allow the prism/mirror to be moved out of the way well in advance of the shutter-curtain actually opening to expose the sensor with light from the lens. This either eliminates the ‘Mirror Slap’ altogether or allows the the vibrations to die down. For example, the Nikon D5100 features ‘Quiet Mode’ which introduces a gap of two seconds between the mirror being pushed away and the shutter opening.
Macro photography is definitely technically challenging and the only way to get better at it is to practice more. As I have illustrated in my article, you do not need expensive gear to practice macro photography but you certainly need ingenuity.
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Macro Photography Products on Amazon:
Tamron 90mm Macro Lens Nikon Mount: [amazonproduct=B00021EE4U]
Kenko Extension Tubes Set for Nikon DSLR: [amazonproduct=B000JG88JU]
Close Up Macro Filter Lens Set: [amazonproduct=B001UE6NAQ]
Raynox DCR-250 Super Macro Snap-On Lens: [amazonproduct=B000A1SZ2Y]
Lens Reverse Mount Adapter for Nikon DSLR: [amazonproduct=B001G4NBSC]
Macro Focusing Rail: [amazonproduct=B0047DS41S]
Ring Flash for Portrait / Macro Photography: [amazonproduct=B003LYIZNG]
Tripod with Horizontal Arm for Macro: [amazonproduct=B000XQ0236]
Amazon aStore with Collection of Lenses for Macro Photography using Nikon Cameras: Click here.
Note: Most of these lenses are also available for other DSLR cameras from Canon, Pentax, Sony, Olympus etc.